A 59-year-old man was admitted with a complaint of epigastric discomfort, under the diagnosis of gastric cancer, subtotal gastrectomy was performed. In the resected specimen IIc + III type early gastric cancer were observed at the lesser curvature of the corpus and multiple submucosal cysts in almost entire area of the stomach. Histologic examination confirmed early adenocarcinoma and an atypical epithelium, which was present separately. Submucosal cysts consisted of a pseudo-pyloric-gland-type of epithelium, containing some fundic glandular and foveolar epithelium. Frequent erosion and regenerated epithelium and extensive intestinal metaplasia were observed in the gastric mucosa. There was no carcinomatous change in the submucosal cysts.